Today, almost 100 million people in the United States are using a smartphone, and the number is growing rapidly. These devices not only have put the Internet in our pockets, but also have altered our ideas of computers as static machines. One of the most important areas of research at MIT concerns ubiquitous computing. During a sabbatical year at Google, professor Hal Abelson invented software that would enable everyone to program an “app” for his or her phone. Google App Inventor (renamed the MIT App Inventor in late 2011 when Google stopped supporting the project) is new, but it represents a key philosophy espoused by Abelson: “If your phone is going to be an influential force in your life, then you should be able to shape it to suit your needs whether or not you have a degree in computer science or electrical engineering.”